局部荷载作用下地铁基坑地表沉降的数值分析

Surface settlement analysis of subway foundation pits under local loads at different locations

以南昌某长条形地铁车站基坑为基础,建立了三维渗流模型模拟基坑实际工况。通过工程实测数据对比,验证该模型的有效性。在此基础上,研究了不同位置的局部荷载对预降水过程中,坑外地表沉降分布的影响。分析结果表明,局部荷载会造成荷载侧一定范围内地表沉降量增加,非荷载侧一定范围内地表沉降量减小;局部荷载对基坑荷载侧影响范围最大为3倍荷载长度,对基坑非荷载侧影响范围最大为5倍荷载长度;荷载侧地表沉降量最大增加18.7%,而非荷载侧地表沉降量减小约7%。

Based on the foundation pit of a long-strip subway station in Nanchang,a three-dimensional seepage model is established to simulate it,and the effectiveness of the model is verified by comparing the actual measurement data of the project.On this basis,the effects of different positions of local loads on the sedimentation distribution of pit surfaces during pre-precipitation are studied.The results show that the local load will cause the increase of surface settlement in a certain range of the load side,and the decrease of surface settlement in a certain range of the non-load side;The maximum range of influence of local load on the load side of foundation pit is 3 times the load length,and the maximum range of influence on the non-load side of foundation pit is 5 times the load length;The maximum increase of surface settlement on the load side is 18.7%,while the decrease of surface settlement on the non-load side is about 7%.